The Ultimax Disc's black zinc coating protects against rust and under the industry standard salt spray testing was proven to last anywhere between 2 and 5 years dependant on conditions. The USR Series offers discs that are almost totally silent ideal for prestige and premium cars. The discs have the latest super quiet slot pattern reducing disc wind noise. The pattern allows smooth wear for the life of the brake pad which inturn improves braking performance. Want the quietest and brake dust free setup? Use the Ultimax discs with Redstuff pads